Perić, S., Praćenje radnih svojstava maziva u primeni, pp. 59-81 PRAĆENJE RADNIH SVOJSTAVA MAZIVA U PRIMENI Sreten R. Perić, Univerzitet odbrane u Beogradu, Vojna akademija, Katedra vojnomašinskog inženjerstva, Beograd Sažetak: Potreba za što efikasnijim održavanjem i mogućnošću kontinuiranog korišćenja opreme razvila je čitav niz strategija i metoda održavanja opreme. Strategija održavanja po stanju, koja zahteva stalno praćenje i uvid u stanje opreme, uslovila je razvoj i primenu analize maziva. Praćenje radnih svojstava maziva u primeni ima višestruki značaj i za korisnika i za proizvođača maziva. Za korisnika je to prvenstveno produžena i pravovremena zamena maziva, što čini troškove održavanja nižim. Za proizvođača maziva predstavlja stvaranje partnerskih odnosa s potrošačem, ali i mogućnost prikupljanja informacija o ponašanju sopstvenih proizvoda kao podloge za daljnje unapređenje i razvoj proizvoda. Ako se tehnički sistemi žele održavati tako da imaju što manje zastoja i troškova koji slede zbog otklanjanja zastoja i zbog toga što sistem ne obavlja svoju funkciju, onda tokom celog rada sistema treba pratiti podatke koji govore o stanju ispravnosti opreme. Posebno je teško dobiti podatke o stanju opreme kod onih delova koji su nepristupačni za posmatranje. U tim slučajevima analiza ulja omogućuje kontinuirano praćenje stanja opreme i delovanje na vreme radi sprečavanja neželjenih dugotrajnih zastoja. Ključne reči: monitoring, održavanje, analiza ulja.Uvod snovna uloga maziva, odnosno podmazivanja, jeste da se smanji trenje, te ujedno spreči habanje površina materijala koje se nalaze u međusobno relativnom kretanju. Ali, neophodno je da mazivo poseduje i ostala funkcionalna svojstva koja će osigurati njegovu efikasnu primenu. To je, pre svega, dobra oksidaciono-termička stabilnost, svojstvo zaštite od korozije, kompatibilnost s različitim materijalima, mala O

During the past few decades, special attention has been devoted to developing modern instruments and methods of monitoring the tribomechanical characteristics of technical systems. Today, various physical, chemical and tribological methods are used in tribomechanical systems diagnosis. Scientific experience in technical system exploitation and maintenance has shown that the most effective way to predict failure is based on parameters that are reliable indicators of wear. Analysis of oil samples, which contain particles due to the wear process, enables an evaluation of the tribology condition of the system in the early phases of its use. This paper deals with tribological tests that are part of the oil analysis and are used to access the condition of the system. Furthermore, the results of experimental research on the tribological characteristics of the oil sampled from engines and gear transmissions of the vehicles (Mercedes O 345, PUCH 300GD and PINZGAUER 710M) are shown. All of these road vehicle were in regular use by the Serbian armed forces. The performed research has revealed some significant changes in the tribological characteristics of oil for engine and gear transmission lubrication.. These changes directly depend on the condition of the entire engine and transmission elements, i.e. depend on their functional characteristics. The presented method of oil analysis should contribute to an early detection of failures due to friction and wear processes in vehicle engines and reduce the need for preventive maintenance.

Abstract:The most common chemical's spills in typical transportation accidents are those with petroleum products such as diesel fuel, the consequence of which is an extensive pollution of the soil. In order to plan properly fuel recovery from the soil, it is important to gain information about the soil depth which may be affected by pollutant and to predict the pollutant concentration in different soil layers. This study deals with the impact of basic atmospheric conditions, i.e. air temperature and humidity on the diesel fuel migration through the soil. The diesel fuel was spilled into columns (L = 30 cm; D = 4.6 cm) fi lled with sandy and clay soil samples, and its concentrations at various depths were measured after 11 days under various air temperature (20 and 40°C) and relative humidity (30-100%) conditions. The effects observed were explained by understanding physical processes, such as fuel evaporation, diffusion and adsorption on soil grains. The increase in temperature results in higher fuel evaporation loss and its faster vertical migration. The relative humidity effect is less pronounced but more complex, and it depends much on the soil type.

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In the study of ways to reduce the friction losses of internal combustion (IC) engines, investigations of losses from elements in the piston assembly, the bearing system, and the valve train system are paramount. Mechanical and thermodynamic losses, wear and the emissions caused by lubricating oil combustion are principally influenced by the tribological behaviour of the piston assembly. The tribological performance of piston rings in reciprocating IC engines can only be fully understood when both lubrication and wear are considered in combination. This paper deals with physical-chemical tests that are part of the oil analysis and are used to access the condition of the system. Furthermore, the results of experimental research on the physical-chemical properties of the oil sampled from engines of the vehicles are shown.